Microsurvey

Time-Domain Electromagnetometry

The electromagnetic method measures the magnetic field falloff in a surface induced by an external source (transmitter). Thus, induced currents in geological zones with conductive properties, originated from the primary external magnetic field, produce a secondary magnetic field that slowly falls off after the external source's interruption. Such fall off has its manner defined by the size, depth and conductance of the geological mean.

This technique is ideal for the detection of mineralizations of massive sulphide deposits. In terms of electrical properties, TDEM provides a strong response when there is a continuity between the metallic mineral grains or also in the presence of failures and porous rocks filled in with conductive fluids.

The great advantage in the use of the time domain electromagnetic method is the sequence of response signal distributed in time channels, which enables us to determine the depth of conductive bodies, as well as its form and dip position.

The time-domain electromagnetic air model used jointly with the Magnetometric method allows us to separate ferrous metals from non ferrous ones, such as sulphides